Toyota Repair: 5th Gear Failure in 2002 RAV4 Manual transmission, good mileage, repair toyota

Question
2002 Manual RAV4 AWD currently @ 159000km. All maintenance has been done on schedule and with local Toyota.
-May 2009 @ 124000km: stick shift vibration in 5th gear.  Toyota suspected sychro gear, advised I could drive until gear failed.
-Dec. 2009 @ 134000km: 5th gear started to move several cm whenever I lifted my foot from the accelerator for several months before 5th gear popped out and failed entirely. Toyota service said too much play in 5th gear, needed to replace gear or transmission.
-Jan 2010 5th gear replaced:  6 hours labour + $1000 CAD parts.  After researching we asked tech to come in from the side rather than taking the transmission out and re-building.  They also recommended 4th gear replacement "just in case or 5th would fail again."  Stick shift still had some vibration after the repair.  Toyota told us it was "normal".
-Oct. 2010 @ 147000km more significant vibration- again "normal" for the RAV, according to Toyota
-Feb to March 2011 @ 158000km, stick shift moved back and forth in 5th gear again then 5th gear popped out and failed.
Toyota dealership now under new ownership with new service personnel.  
They say:
 -we should have replaced transmission right at the start of our 5th gear problems and they cannot honour what was done under the former management and servicing.
 -we can only replace entire transmission now. There are no rebuilts available, a used has 90-day warranty and 77000km on the tranny @ $1500CAD + 13.6 hrs. labour, new will cost $3500 CAD + labour, not told yet what the warranty is.
 -we were told 5th gear manual transmission failure is an unusual problem for the RAV and a used should give us good mileage and service.
We live in NE British Columbia and do not have other Toyota service centres for 2nd opinions. We are not hard on our vehicles and do most of our driving on highways 40 km into town. I am pretty discouraged after having a good history with other Toyotas (2002 ECHO, 1985 Tercel 4WD went to 400000km on original engine and transmission) and do not know what to do next.
Any thoughts?
Thank you for your assistance.

Answer
It is unusual to have a transmission problem like this with the Rav 4 at this mileage but it seems there is no recourse with the new dealer, there is no way to know what the previous dealer actually did to fix this but it sounds like it wan't done right and I agree the transmission probably should have been replaced in the first place, I would opt for the used transmission or trade it in as is on another vehicle.